--- /dev/null
+/*
+ * ST M48T59 RTC driver
+ *
+ * Copyright (c) 2007 Wind River Systems, Inc.
+ *
+ * Author: Mark Zhan <rongkai.zhan@windriver.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+#include <linux/rtc/m48t59.h>
+#include <linux/bcd.h>
+#include <linux/slab.h>
+
+#ifndef NO_IRQ
+#define NO_IRQ (-1)
+#endif
+
+#define M48T59_READ(reg) (pdata->read_byte(dev, pdata->offset + reg))
+#define M48T59_WRITE(val, reg) \
+ (pdata->write_byte(dev, pdata->offset + reg, val))
+
+#define M48T59_SET_BITS(mask, reg) \
+ M48T59_WRITE((M48T59_READ(reg) | (mask)), (reg))
+#define M48T59_CLEAR_BITS(mask, reg) \
+ M48T59_WRITE((M48T59_READ(reg) & ~(mask)), (reg))
+
+struct m48t59_private {
+ void __iomem *ioaddr;
+ int irq;
+ struct rtc_device *rtc;
+ spinlock_t lock; /* serialize the NVRAM and RTC access */
+};
+
+/*
+ * This is the generic access method when the chip is memory-mapped
+ */
+static void
+m48t59_mem_writeb(struct device *dev, u32 ofs, u8 val)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
+
+ writeb(val, m48t59->ioaddr+ofs);
+}
+
+static u8
+m48t59_mem_readb(struct device *dev, u32 ofs)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
+
+ return readb(m48t59->ioaddr+ofs);
+}
+
+/*
+ * NOTE: M48T59 only uses BCD mode
+ */
+static int m48t59_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct m48t59_plat_data *pdata = dev_get_platdata(&pdev->dev);
+ struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
+ unsigned long flags;
+ u8 val;
+
+ spin_lock_irqsave(&m48t59->lock, flags);
+ /* Issue the READ command */
+ M48T59_SET_BITS(M48T59_CNTL_READ, M48T59_CNTL);
+
+ tm->tm_year = bcd2bin(M48T59_READ(M48T59_YEAR));
+ /* tm_mon is 0-11 */
+ tm->tm_mon = bcd2bin(M48T59_READ(M48T59_MONTH)) - 1;
+ tm->tm_mday = bcd2bin(M48T59_READ(M48T59_MDAY));
+
+ val = M48T59_READ(M48T59_WDAY);
+ if ((pdata->type == M48T59RTC_TYPE_M48T59) &&
+ (val & M48T59_WDAY_CEB) && (val & M48T59_WDAY_CB)) {
+ dev_dbg(dev, "Century bit is enabled\n");
+ tm->tm_year += 100; /* one century */
+ }
+#ifdef CONFIG_SPARC
+ /* Sun SPARC machines count years since 1968 */
+ tm->tm_year += 68;
+#endif
+
+ tm->tm_wday = bcd2bin(val & 0x07);
+ tm->tm_hour = bcd2bin(M48T59_READ(M48T59_HOUR) & 0x3F);
+ tm->tm_min = bcd2bin(M48T59_READ(M48T59_MIN) & 0x7F);
+ tm->tm_sec = bcd2bin(M48T59_READ(M48T59_SEC) & 0x7F);
+
+ /* Clear the READ bit */
+ M48T59_CLEAR_BITS(M48T59_CNTL_READ, M48T59_CNTL);
+ spin_unlock_irqrestore(&m48t59->lock, flags);
+
+ dev_dbg(dev, "RTC read time %04d-%02d-%02d %02d/%02d/%02d\n",
+ tm->tm_year + 1900, tm->tm_mon, tm->tm_mday,
+ tm->tm_hour, tm->tm_min, tm->tm_sec);
+ return rtc_valid_tm(tm);
+}
+
+static int m48t59_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct m48t59_plat_data *pdata = dev_get_platdata(&pdev->dev);
+ struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
+ unsigned long flags;
+ u8 val = 0;
+ int year = tm->tm_year;
+
+#ifdef CONFIG_SPARC
+ /* Sun SPARC machines count years since 1968 */
+ year -= 68;
+#endif
+
+ dev_dbg(dev, "RTC set time %04d-%02d-%02d %02d/%02d/%02d\n",
+ year + 1900, tm->tm_mon, tm->tm_mday,
+ tm->tm_hour, tm->tm_min, tm->tm_sec);
+
+ if (year < 0)
+ return -EINVAL;
+
+ spin_lock_irqsave(&m48t59->lock, flags);
+ /* Issue the WRITE command */
+ M48T59_SET_BITS(M48T59_CNTL_WRITE, M48T59_CNTL);
+
+ M48T59_WRITE((bin2bcd(tm->tm_sec) & 0x7F), M48T59_SEC);
+ M48T59_WRITE((bin2bcd(tm->tm_min) & 0x7F), M48T59_MIN);
+ M48T59_WRITE((bin2bcd(tm->tm_hour) & 0x3F), M48T59_HOUR);
+ M48T59_WRITE((bin2bcd(tm->tm_mday) & 0x3F), M48T59_MDAY);
+ /* tm_mon is 0-11 */
+ M48T59_WRITE((bin2bcd(tm->tm_mon + 1) & 0x1F), M48T59_MONTH);
+ M48T59_WRITE(bin2bcd(year % 100), M48T59_YEAR);
+
+ if (pdata->type == M48T59RTC_TYPE_M48T59 && (year / 100))
+ val = (M48T59_WDAY_CEB | M48T59_WDAY_CB);
+ val |= (bin2bcd(tm->tm_wday) & 0x07);
+ M48T59_WRITE(val, M48T59_WDAY);
+
+ /* Clear the WRITE bit */
+ M48T59_CLEAR_BITS(M48T59_CNTL_WRITE, M48T59_CNTL);
+ spin_unlock_irqrestore(&m48t59->lock, flags);
+ return 0;
+}
+
+/*
+ * Read alarm time and date in RTC
+ */
+static int m48t59_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct m48t59_plat_data *pdata = dev_get_platdata(&pdev->dev);
+ struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
+ struct rtc_time *tm = &alrm->time;
+ unsigned long flags;
+ u8 val;
+
+ /* If no irq, we don't support ALARM */
+ if (m48t59->irq == NO_IRQ)
+ return -EIO;
+
+ spin_lock_irqsave(&m48t59->lock, flags);
+ /* Issue the READ command */
+ M48T59_SET_BITS(M48T59_CNTL_READ, M48T59_CNTL);
+
+ tm->tm_year = bcd2bin(M48T59_READ(M48T59_YEAR));
+#ifdef CONFIG_SPARC
+ /* Sun SPARC machines count years since 1968 */
+ tm->tm_year += 68;
+#endif
+ /* tm_mon is 0-11 */
+ tm->tm_mon = bcd2bin(M48T59_READ(M48T59_MONTH)) - 1;
+
+ val = M48T59_READ(M48T59_WDAY);
+ if ((val & M48T59_WDAY_CEB) && (val & M48T59_WDAY_CB))
+ tm->tm_year += 100; /* one century */
+
+ tm->tm_mday = bcd2bin(M48T59_READ(M48T59_ALARM_DATE));
+ tm->tm_hour = bcd2bin(M48T59_READ(M48T59_ALARM_HOUR));
+ tm->tm_min = bcd2bin(M48T59_READ(M48T59_ALARM_MIN));
+ tm->tm_sec = bcd2bin(M48T59_READ(M48T59_ALARM_SEC));
+
+ /* Clear the READ bit */
+ M48T59_CLEAR_BITS(M48T59_CNTL_READ, M48T59_CNTL);
+ spin_unlock_irqrestore(&m48t59->lock, flags);
+
+ dev_dbg(dev, "RTC read alarm time %04d-%02d-%02d %02d/%02d/%02d\n",
+ tm->tm_year + 1900, tm->tm_mon, tm->tm_mday,
+ tm->tm_hour, tm->tm_min, tm->tm_sec);
+ return rtc_valid_tm(tm);
+}
+
+/*
+ * Set alarm time and date in RTC
+ */
+static int m48t59_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct m48t59_plat_data *pdata = dev_get_platdata(&pdev->dev);
+ struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
+ struct rtc_time *tm = &alrm->time;
+ u8 mday, hour, min, sec;
+ unsigned long flags;
+ int year = tm->tm_year;
+
+#ifdef CONFIG_SPARC
+ /* Sun SPARC machines count years since 1968 */
+ year -= 68;
+#endif
+
+ /* If no irq, we don't support ALARM */
+ if (m48t59->irq == NO_IRQ)
+ return -EIO;
+
+ if (year < 0)
+ return -EINVAL;
+
+ /*
+ * 0xff means "always match"
+ */
+ mday = tm->tm_mday;
+ mday = (mday >= 1 && mday <= 31) ? bin2bcd(mday) : 0xff;
+ if (mday == 0xff)
+ mday = M48T59_READ(M48T59_MDAY);
+
+ hour = tm->tm_hour;
+ hour = (hour < 24) ? bin2bcd(hour) : 0x00;
+
+ min = tm->tm_min;
+ min = (min < 60) ? bin2bcd(min) : 0x00;
+
+ sec = tm->tm_sec;
+ sec = (sec < 60) ? bin2bcd(sec) : 0x00;
+
+ spin_lock_irqsave(&m48t59->lock, flags);
+ /* Issue the WRITE command */
+ M48T59_SET_BITS(M48T59_CNTL_WRITE, M48T59_CNTL);
+
+ M48T59_WRITE(mday, M48T59_ALARM_DATE);
+ M48T59_WRITE(hour, M48T59_ALARM_HOUR);
+ M48T59_WRITE(min, M48T59_ALARM_MIN);
+ M48T59_WRITE(sec, M48T59_ALARM_SEC);
+
+ /* Clear the WRITE bit */
+ M48T59_CLEAR_BITS(M48T59_CNTL_WRITE, M48T59_CNTL);
+ spin_unlock_irqrestore(&m48t59->lock, flags);
+
+ dev_dbg(dev, "RTC set alarm time %04d-%02d-%02d %02d/%02d/%02d\n",
+ year + 1900, tm->tm_mon, tm->tm_mday,
+ tm->tm_hour, tm->tm_min, tm->tm_sec);
+ return 0;
+}
+
+/*
+ * Handle commands from user-space
+ */
+static int m48t59_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct m48t59_plat_data *pdata = dev_get_platdata(&pdev->dev);
+ struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
+ unsigned long flags;
+
+ spin_lock_irqsave(&m48t59->lock, flags);
+ if (enabled)
+ M48T59_WRITE(M48T59_INTR_AFE, M48T59_INTR);
+ else
+ M48T59_WRITE(0x00, M48T59_INTR);
+ spin_unlock_irqrestore(&m48t59->lock, flags);
+
+ return 0;
+}
+
+static int m48t59_rtc_proc(struct device *dev, struct seq_file *seq)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct m48t59_plat_data *pdata = dev_get_platdata(&pdev->dev);
+ struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
+ unsigned long flags;
+ u8 val;
+
+ spin_lock_irqsave(&m48t59->lock, flags);
+ val = M48T59_READ(M48T59_FLAGS);
+ spin_unlock_irqrestore(&m48t59->lock, flags);
+
+ seq_printf(seq, "battery\t\t: %s\n",
+ (val & M48T59_FLAGS_BF) ? "low" : "normal");
+ return 0;
+}
+
+/*
+ * IRQ handler for the RTC
+ */
+static irqreturn_t m48t59_rtc_interrupt(int irq, void *dev_id)
+{
+ struct device *dev = (struct device *)dev_id;
+ struct platform_device *pdev = to_platform_device(dev);
+ struct m48t59_plat_data *pdata = dev_get_platdata(&pdev->dev);
+ struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
+ u8 event;
+
+ spin_lock(&m48t59->lock);
+ event = M48T59_READ(M48T59_FLAGS);
+ spin_unlock(&m48t59->lock);
+
+ if (event & M48T59_FLAGS_AF) {
+ rtc_update_irq(m48t59->rtc, 1, (RTC_AF | RTC_IRQF));
+ return IRQ_HANDLED;
+ }
+
+ return IRQ_NONE;
+}
+
+static const struct rtc_class_ops m48t59_rtc_ops = {
+ .read_time = m48t59_rtc_read_time,
+ .set_time = m48t59_rtc_set_time,
+ .read_alarm = m48t59_rtc_readalarm,
+ .set_alarm = m48t59_rtc_setalarm,
+ .proc = m48t59_rtc_proc,
+ .alarm_irq_enable = m48t59_rtc_alarm_irq_enable,
+};
+
+static const struct rtc_class_ops m48t02_rtc_ops = {
+ .read_time = m48t59_rtc_read_time,
+ .set_time = m48t59_rtc_set_time,
+};
+
+static ssize_t m48t59_nvram_read(struct file *filp, struct kobject *kobj,
+ struct bin_attribute *bin_attr,
+ char *buf, loff_t pos, size_t size)
+{
+ struct device *dev = container_of(kobj, struct device, kobj);
+ struct platform_device *pdev = to_platform_device(dev);
+ struct m48t59_plat_data *pdata = dev_get_platdata(&pdev->dev);
+ struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
+ ssize_t cnt = 0;
+ unsigned long flags;
+
+ for (; size > 0 && pos < pdata->offset; cnt++, size--) {
+ spin_lock_irqsave(&m48t59->lock, flags);
+ *buf++ = M48T59_READ(cnt);
+ spin_unlock_irqrestore(&m48t59->lock, flags);
+ }
+
+ return cnt;
+}
+
+static ssize_t m48t59_nvram_write(struct file *filp, struct kobject *kobj,
+ struct bin_attribute *bin_attr,
+ char *buf, loff_t pos, size_t size)
+{
+ struct device *dev = container_of(kobj, struct device, kobj);
+ struct platform_device *pdev = to_platform_device(dev);
+ struct m48t59_plat_data *pdata = dev_get_platdata(&pdev->dev);
+ struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
+ ssize_t cnt = 0;
+ unsigned long flags;
+
+ for (; size > 0 && pos < pdata->offset; cnt++, size--) {
+ spin_lock_irqsave(&m48t59->lock, flags);
+ M48T59_WRITE(*buf++, cnt);
+ spin_unlock_irqrestore(&m48t59->lock, flags);
+ }
+
+ return cnt;
+}
+
+static struct bin_attribute m48t59_nvram_attr = {
+ .attr = {
+ .name = "nvram",
+ .mode = S_IRUGO | S_IWUSR,
+ },
+ .read = m48t59_nvram_read,
+ .write = m48t59_nvram_write,
+};
+
+static int m48t59_rtc_probe(struct platform_device *pdev)
+{
+ struct m48t59_plat_data *pdata = dev_get_platdata(&pdev->dev);
+ struct m48t59_private *m48t59 = NULL;
+ struct resource *res;
+ int ret = -ENOMEM;
+ char *name;
+ const struct rtc_class_ops *ops;
+
+ /* This chip could be memory-mapped or I/O-mapped */
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ res = platform_get_resource(pdev, IORESOURCE_IO, 0);
+ if (!res)
+ return -EINVAL;
+ }
+
+ if (res->flags & IORESOURCE_IO) {
+ /* If we are I/O-mapped, the platform should provide
+ * the operations accessing chip registers.
+ */
+ if (!pdata || !pdata->write_byte || !pdata->read_byte)
+ return -EINVAL;
+ } else if (res->flags & IORESOURCE_MEM) {
+ /* we are memory-mapped */
+ if (!pdata) {
+ pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata),
+ GFP_KERNEL);
+ if (!pdata)
+ return -ENOMEM;
+ /* Ensure we only kmalloc platform data once */
+ pdev->dev.platform_data = pdata;
+ }
+ if (!pdata->type)
+ pdata->type = M48T59RTC_TYPE_M48T59;
+
+ /* Try to use the generic memory read/write ops */
+ if (!pdata->write_byte)
+ pdata->write_byte = m48t59_mem_writeb;
+ if (!pdata->read_byte)
+ pdata->read_byte = m48t59_mem_readb;
+ }
+
+ m48t59 = devm_kzalloc(&pdev->dev, sizeof(*m48t59), GFP_KERNEL);
+ if (!m48t59)
+ return -ENOMEM;
+
+ m48t59->ioaddr = pdata->ioaddr;
+
+ if (!m48t59->ioaddr) {
+ /* ioaddr not mapped externally */
+ m48t59->ioaddr = devm_ioremap(&pdev->dev, res->start,
+ resource_size(res));
+ if (!m48t59->ioaddr)
+ return ret;
+ }
+
+ /* Try to get irq number. We also can work in
+ * the mode without IRQ.
+ */
+ m48t59->irq = platform_get_irq(pdev, 0);
+ if (m48t59->irq <= 0)
+ m48t59->irq = NO_IRQ;
+
+ if (m48t59->irq != NO_IRQ) {
+ ret = devm_request_irq(&pdev->dev, m48t59->irq,
+ m48t59_rtc_interrupt, IRQF_SHARED,
+ "rtc-m48t59", &pdev->dev);
+ if (ret)
+ return ret;
+ }
+ switch (pdata->type) {
+ case M48T59RTC_TYPE_M48T59:
+ name = "m48t59";
+ ops = &m48t59_rtc_ops;
+ pdata->offset = 0x1ff0;
+ break;
+ case M48T59RTC_TYPE_M48T02:
+ name = "m48t02";
+ ops = &m48t02_rtc_ops;
+ pdata->offset = 0x7f0;
+ break;
+ case M48T59RTC_TYPE_M48T08:
+ name = "m48t08";
+ ops = &m48t02_rtc_ops;
+ pdata->offset = 0x1ff0;
+ break;
+ default:
+ dev_err(&pdev->dev, "Unknown RTC type\n");
+ return -ENODEV;
+ }
+
+ spin_lock_init(&m48t59->lock);
+ platform_set_drvdata(pdev, m48t59);
+
+ m48t59->rtc = devm_rtc_device_register(&pdev->dev, name, ops,
+ THIS_MODULE);
+ if (IS_ERR(m48t59->rtc))
+ return PTR_ERR(m48t59->rtc);
+
+ m48t59_nvram_attr.size = pdata->offset;
+
+ ret = sysfs_create_bin_file(&pdev->dev.kobj, &m48t59_nvram_attr);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static int m48t59_rtc_remove(struct platform_device *pdev)
+{
+ sysfs_remove_bin_file(&pdev->dev.kobj, &m48t59_nvram_attr);
+ return 0;
+}
+
+/* work with hotplug and coldplug */
+MODULE_ALIAS("platform:rtc-m48t59");
+
+static struct platform_driver m48t59_rtc_driver = {
+ .driver = {
+ .name = "rtc-m48t59",
+ },
+ .probe = m48t59_rtc_probe,
+ .remove = m48t59_rtc_remove,
+};
+
+module_platform_driver(m48t59_rtc_driver);
+
+MODULE_AUTHOR("Mark Zhan <rongkai.zhan@windriver.com>");
+MODULE_DESCRIPTION("M48T59/M48T02/M48T08 RTC driver");
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff